These jaws come with a screw, but the screw diameter is too big for the pliers, so this replacement is worthless. I wish I'd put the money towards a new pair of pliers instead. The original screws are too short to go through both the jaw and pliers. Will be returning this product.
I didn't actually order the proper fitting replacement heads for the pliers I have, and yet these heads still work well on them. Despite the fact that they are a little loose because I got the wrong size, they are still secure enough to be functional.